Newsprint and other paper used for printing are generally shipped from the paper mill in large rolls. When the rolls are made up at the paper mill, they are wound on a tubular core. Typically, the cores are made of liner and/or chip board.
In the press room or other paper process plant, the roll is mounted on an unwind apparatus with the core of the roll journaled on chucks. Once the web of paper has been unwound from the core, the core is generally discarded or returned to a paper mill to be recycled as waste fiber.
Thus, until recently, it has not been contemplated to reuse a winding core once it has been utilized, other than to cut the core down to a smaller size. Indeed, it has been found that after a single use, the winding core is somewhat damaged. More particularly, the internal extremities of the core which have been crimped during unwinding are damaged and cannot be conveniently journaled on chucks once again. Thus, the practice in the industry is to discard the winding cores once a roll of paper web has been unwound therefrom. The discarded single use winding core is then returned to the paper mill as scrap liner board to be recycled as paper fiber.
FIG. 1 (PRIOR ART), illustrates a paper roll 10 having a winding core 12 journaled on chucks 14 at crimping portions 16, 18. The two chucks 14 support the core 12 and control the rotation of the paper roll 10, as well known in the art. Once the paper has been unrolled from the core 12, the core is intact on its length but is damaged at its internal extremities known as the crimping portions 16, 18.
Known in the art, there are U.S. Pat. Nos. 5,845,871 and 6,051,092, both granted to Lynch et al., which describe a recycled core for winding paper, a method for manufacturing the same and an apparatus for recycling cores. FIGS. 2A to 2E (PRIOR ART) illustrate the conventional prior art method described in the above-mentioned US patents used for manufacturing recycled winding cores. Discarded winding cores 12 are first collected, as illustrated on FIG. 2A. The ends 20, 22 of the core 12 which comprise the crimping portions 16, 18 are then trimmed to remove the crimping portions 16, 18 off the core 12, as illustrated on FIG. 2B. FIG. 2C illustrates a trimmed core 24 which is undamaged and smaller than the original core 12. At this point, a female joint socket 26 is formed at one end of the core 24 while a complementary male joint socket 28 is formed at the other end of the core 24, as illustrated on FIG. 2D. A plurality of such cores 24 are then joined end to end with adhesive to form an elongated multiple-length core master 30, as illustrated on FIG. 2E. An elongated web of finishing material (not shown) equivalent to the length of the multi-length core master 30 and having a width corresponding to the circumference of the core master 30 is then wrapped around the core master 30 with adhesive so as to provide a finished core master. The extremities 32, 34 of the core master 30 are finally trimmed so as to remove the two opposed joint sockets 26, 28, as illustrated on FIG. 2E. The core master 30 can then be cut into recycled winding cores of suitable length. U.S. Pat. No. 6,453,966, which comes from the two above-mentioned US patents, describes an apparatus for wrapping a layer of material on such recycled cores.
These patents provide great improvement over the prior art since most of the length of the core can be recycled. However, with the above-described method, the whole length of the core still cannot be entirely recycled. Moreover, this method requires a complex equipment to machine the cores. In fact, with such a method, a specific machine is used for manufacturing a recycled core of a predetermined length. Thus, to manufacture a recycled core of another length, another specific machine would be required. The same issue arises concerning the diameter of the recycled core since a specific grinding tool is required to form the joint sockets.
Also of interest, there is PCT application No. PCT/JP97/01125, published under publication No. WO98/43908, which describes a winding core, a method for producing the same and an insert member for producing the winding core. Also of interest, there is Japanese patent application No. 2002-006953 published under publication No. 2003-206079 which describes a recycled paper tube and its manufacturing method.
However, these two above-mentioned patent applications still do not allow to recycle the whole length of the used cores in an easy and economical manner.
Therefore, it would be desirable to provide an improved method and an apparatus for economically and easily reclaiming discarded winding cores to acceptable standards such that the restored winding cores can be reused as winding cores.